1. Field of the Invention
The present invention relates to a transmitting/receiving apparatus of down-link data using an automatic repeat request (ARQ) scheme and method thereof in a wireless communication system. More particularly, the present invention relates to a method for transmitting an ARQ feedback acknowledgement message for down-link traffic from a base station to a terminal.
2. Description of the Related Art
In a wireless communication system, an automatic repeat request (hereinafter, called “ARQ”) scheme, that is, an error controlling protocol for requesting a data retransmission when a transmitter or receiver detects a data error generated in a transmission line, includes a selective repeat ARQ scheme for retransmitting only erroneous parts, a cumulative-ARQ, a cumulative with selective-ARQ, and a cumulative with bulk-ARQ scheme. These respective ARQ schemes require an ARQ feedback acknowledgement message indicating whether an ARQ service receiver correctly receives an ARQ block from the ARQ service translator.
A wireless communication system including such an ARQ scheme uses a time division multiple access (TDMA) scheme as a transmission scheme, and it is accordingly configured such that the terminal additionally performs a radio resource allocation request process to the base station so as to transmit up-link data. In addition, general web traffic is asymmetric in that an amount of down-link traffic is very much larger than that of up-link traffic. The down-link traffic relates to traffic transmitted from the base station to the terminal, and the up-link traffic relates to traffic transmitted from the terminal to the base station.
Therefore, a down-link traffic speed among service flows performing ARQ services is considerably dependent on up-link feedback response speed. The reason that a limited size of window is saturated in the case of delaying the update is that the transmitter can transmit the ARQ services only within the ARQ window and an update is performed by the ARQ feedback acknowledgment.
In addition, generally, a wireless communication system for providing a web service uses the TDMA scheme at the down-link for transmitting a large amount of data. Accordingly, there is a problem in that a large delay occurs because the terminal must perform a radio resource allocation process so as to transmit an ARQ feedback response to the up-link.
In addition, because of Internet traffic characteristic, excessive data are transmitted at a predetermined point. When the ARQ service transmitter window receives an ARQ feedback acknowledgement message transmitted from the ARQ service receiver late, it is easy for the ARQ feedback acknowledgement message to exceed the maximum size of the transmitter window. Accordingly, at this time, there is a problem in that the ARQ feedback acknowledgment message is not transmitted to the ARQ service receiver.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.